Novel strong acids, process for the preparation thereof, and uses thereof

ABSTRACT

The present invention relates to acids of the general formula [I], [R y PF 6-y ] −  H + [I] where y=1, 2 or 3, and in which the ligands R may be identical or different and R is a perfluorinated C 1-8 -alkyl or aryl group or R is a partially fluorinated C 1-8 -alkyl or aryl group, in which some of the F or H may have been substituted by chlorine. The present invention furthermore relates to a process for the preparation of the acids according to the invention, to salts comprising a cation and the anion of the acid according to the invention, and to a process for the preparation of the salts. The invention furthermore relates to the use of the acids and salts according to the invention.

[0001] The present invention relates to acids of the general formula [I]

[R_(y)PF_(6-y)]⁻H⁺  [I]

[0002] where

[0003] y=1, 2 or 3,

[0004] and in which

[0005] the ligands R may be identical or different, and

[0006] R is a perfluorinated C₁₋₈-alkyl or aryl group or R is apartially fluorinated C₁₋₈-alkyl or aryl group in which some of the F orH may have been substituted by chlorine.

[0007] The present invention furthermore relates to a process for thepreparation of the acids according to the invention, to salts comprisinga cation and the anion of one of the acids according to the invention,and to a process for the preparation of the salts. The inventionfurthermore relates to the use of the acids and metal salts according tothe invention.

[0008] Hexafluorophosphoric acid, HPF₆, is used as a catalyst in organicchemistry or as a starting compound for the preparation of varioussalts. In the industry, hexafluorophosphoric acid is obtained byreaction [1] of phosphorus pentoxide and anhydrous hydrofluoric acid.

P₄O₁₀+24 HF→4 HPF₆+10 H₂O  [1]

[0009] Disadvantages of this process are the toxicity and the riskassociated with handling the starting compound hydrogen fluoride, andthe highly exothermic evolution of heat in the reaction.

[0010] Hexafluorophosphoric acid is commercially available as a 65% byweight aqueous solution. The solution is unstable at higherconcentrations. Pure hexafluorophosphoric acid can be prepared in liquidsulfur dioxide, but is unstable at room temperature (D.E.C. Colbridge,Phosphorus. An Outline of chemistry, Biochemistry and Technology (SecondEdition) Elsevier Scientific Publishing Comp. Amsterdam-Oxford-New York,1980). The poor stability of highly concentrated hexafluorophosphoricacid solutions limits the potential uses of this acid as a catalyst. Inaddition, the coordination of the proton with the phosphorushexafluoride anion reduces the proton activity of this acid.

[0011] The present invention therefore has the object of providingfluorophosphoric acid compounds which do not have the disadvantages ofthe prior art.

[0012] This object is achieved by an acid of the general formula [I]

[R_(y)PF_(6-y)]⁻H⁺  [I]

[0013] where

[0014] y=1, 2 or 3,

[0015] and in which

[0016] the ligands R may be identical or different, and

[0017] R is a perfluorinated C₁₋₈-alkyl or aryl group or R is apartially fluorinated C₁₋₈-alkyl or aryl group in which some of the F orH may have been substituted by chlorine.

[0018] The perfluorinated and the partially fluorinated alkyl or arylgroups R may be in the form of chain or ring structures.

[0019] Preference is given to acids in which at least one group R is aperfluorinated n-, iso-or tert-butyl group or a pentafluorophenyl groupand is particularly preferably a pentafluoroethyl group. Preference isfurthermore given to acids in which y=2 or 3. Particular preference isgiven to acids in which y=3.

[0020] Particular preference is given to the acids according to theinvention trifluorotris-(pentafluoroethyl)phosphoric acid,trifluorotris(nonafluoro-n-butyl)phosphoric acid,trifluorotris(heptafluoro-n-propyl)phosphoric acid,tetrafluorobis(nonafluoro-n-butyl)-phosphoric acid,pentafluoro(nonafluoro-n-butyl)phosphoric acid andtetrafluorobis-(heptafluoro-i-propyl)phosphoric acid.

[0021] For the nomenclature of fluorinated phosphoric acids, referenceis made to the IUPAC nomenclature (A Guide to IUPAC Nomenclature ofOrganic Compounds. Recommendations, by R. Panico, W. H. Powell andJean-Claude Richer, Blackwell Science, 1993).

[0022] The acids according to the invention have the advantage over thefluorophosphoric acids known hitherto of being easy to prepare, havinghigh proton activity and being stable at room temperature in highlyconcentrated solution.

[0023] The present invention furthermore relates to a process for thepreparation of the acids according to the invention in which aperfluoroalkylphosphorane is reacted with hydrogen fluoride in thepresence of a suitable solvent and/or proton acceptor.

[0024] The preparation of perfluoroalkylphosphoranes as startingcompounds for the process according to the invention is familiar to theperson skilled in the art from the prior art, for example from GermanPatent Application DE 19 846 636 A1, which is incorporated herein by wayof reference and is thus regarded as part of the disclosure.

[0025] Suitable solvents and/or proton acceptors for the processesaccording to the invention are preferably compounds having one, two ormore of the following atoms: O, N, S, P, Se, Te and As.

[0026] Preference is given to water, alcohols, ethers, sulfides, amines,phosphines, carboxylic acids, esters, glycols, polyglycols, polyamines,polysulfides or mixtures of at least two of these solvents and/or protonacceptors.

[0027] Particularly preferred solvents and/or proton acceptors arewater, methanol, ethanol, acetic acid, dimethyl ether, diethyl ether,dimethyl carbonate, dimethyl sulfide, dimethylformamide, triethylamineor triphenylphosphine, or mixtures of at least 2 of these compounds.

[0028] The concentration of hydrogen fluoride in the suitable solvent ispreferably greater than 0.1% by weight of HF, particularly preferablygreater than 5% by weight of HF and very particularly preferably greaterthan 10% by weight and most preferably greater than 20% by weight, butless than 100% by weight, of HF.

[0029] In a preferred embodiment, the reaction of theperfluoroalkylphosphorane in the processes according to the invention iscarried out at a temperature of from −50 to +100° C., preferably at atemperature of from −35 to +50° C., particularly preferably at from 0 to25° C.

[0030] By means of the process according to the invention, acids of thegeneral formula [I] are readily accessible in high yields.

[0031] The present invention also relates to solutions of the acidsaccording to the invention which have a concentration of greater than 2%by weight, preferably greater than 20% by weight, particularlypreferably greater than 70% by weight, most preferably greater than 80%by weight, of the acid in a suitable solvent.

[0032] The solutions according to the invention, in particular in thehigh concentration ranges, enable proton activities which can only beachieved with difficulty with solutions of other fluorophosphoric acids.This is particularly advantageous on use of the acids according to theinvention in highly concentrated form, for example as catalyst in areaction mixture. A highly concentrated solution also avoids undesireddilution of reaction mixtures.

[0033] The present invention furthermore relates to salts of the generalformula [II]

[R_(y)PF_(6-y)]_(m) ⁻M^(m+)  [II]

[0034] where

[0035] M^(m+) is a monovalent, divalent or trivalent cation,

[0036] m=1, 2 or 3

[0037] and y=1, 2 or 3,

[0038] and in which

[0039] the ligands R may be identical or different, and

[0040] R is a perfluorinated C₁₋₈-alkyl or aryl group or R is apartially fluorinated C₁₋₈-alkyl or aryl group in which some of the F orH may have been substituted by chlorine.

[0041] The cation M^(m+) can be a metal cation or an organic cation.

[0042] Suitable organic cations are known to the person skilled in theart and are described, for example, in German Patent Application DE10109032.3 on pages 4 to 6. This literature is incorporated herein byway of reference and is thus regarded as part of the disclosure.

[0043] The salts of the general formula [II] preferably contain an Li,Zn, Mg, Cu, Ag, ammonium, phosphonium, oxonioum, sulfonium, arsonium,tropilium, a a nitryl cation, a nitrosyl cation or atris(dialkylammino)carbonium cation.

[0044] An advantage of the salts according to the invention is theirgood solubility in organic solvents.

[0045] In a preferred embodiment, these salts are prepared by a processin which an acid according to the invention is reacted in a suitablesolvent with a salt of the general formula [III]

M^(m+)(A)^(m−)  [III]

[0046] where

[0047] M^(m+) is a monovalent, divalent or trivalent cation,

[0048] A is a basic or neutral anion or a mixture of basic anions or amixture of at least one basic and at least one neutral anion,

[0049] and m=1, 2 or 3,

[0050] or with metals, metal hydrides, metal oxides or metal hydroxides.

[0051] The process is preferably carried out using salts of the formula[III] which contain at least one carbonate, chloride, fluoride, formate,acetate or trifluoroacetate anion.

[0052] The process is preferably carried out using anions which formreadily volatile acids, such as, for example, hydrochloric acid, formicacid or acetic acid. In the process, the metals employed are preferablyLi, Na, K, Rb, Mg, Cs, Ca, Sr, Ba, Sc, Y, Yb, La, Al, In, Cd and/or Zn,the oxides employed are preferably Li₂O, Na₂O, K₂O, MgO, CaO, SrO, BaO,Sc₂O₃, Y₂O₃, Yb₂O₃, La₂O₃, Al₂O₃, CdO, ZnO, CuO, FeO and/or Fe₂O₃, thehydroxides employed are preferably LiOH, NaOH, KOH, RbOH, CsOH, Mg(OH)₂,Ca(OH)₂, Sr(OH)₂, Ba(OH)₂, Cd(OH)₂, Zn(OH)₂, Sc(OH)₃, Al(OH)₃ and/orCu(OH)₂ and the hydrides employed are preferably LiH, NaH, CaH₂, YH₃and/or AlH₃.

[0053] The process for the preparation of the salts according to theinvention is simple to carry out and offers high yields.

[0054] In addition, the present invention relates to the use of one ofthe salts according to the invention as catalyst, as phase-transfercatalyst, as solvent, in particular as ionic liquid, or as conductivesalt in the electrolytes of various electrochemical devices.

[0055] The person skilled in the art understands an “ionic liquid” to beorganic compounds having an ionic structure and a low melting point, forexample N,N-dialkylimidazolium salts [C. E. Song, E. J. Roh, Chem. Comm.(Camebridge) 2000, 10, pp. 837-838; J. Howarth, Tetrahedron Lett. 41(2000) 34, pp. 6627-6629; C. E. Song, C. E. Oh, E. J. Roh, D. J. Choo,Chem. Comm. (Camebridge) 2000,18, pp.1743-1744).

[0056] The present invention also relates to the use of an acidaccording to the invention as catalyst in the preparation of organiccompounds.

[0057] The acids according to the invention are particularly suitable asreplacement for the acids HPF₆ and/or HBF₄ in chemical reactions.

[0058] The acids and/or salts according to the invention are preferablyused in one of the following processes:

[0059] Processes for the

[0060] preparation of photosensitive polymers [CA (Chemical Abstracts)110: 15956e],

[0061] preparation of dihydroxydiaryl compounds [CA 110: 94679t],

[0062] surface treatment of metals [CA 110: 139975e],

[0063] preparation of electrically conductive aniline polymers [CA 110:155067r],

[0064] preparation of carboxylic acids and carboxylic acid esters [CA110: 233613g],

[0065] preparation of high-molecular-weight diazonium compounds [CA 110:87472n],

[0066] preparation of epoxy resins [CA 111: 135490r],

[0067] preparation of electrically conductive materials from amine-likecompounds [CA 112: 46758n],

[0068] preparation of octadienols [CA 112: 98016p],

[0069] carboamination or carboamidation of olefins [CA 112: 161007d],

[0070] isomerisation of butenes [CA 112: 157653u],

[0071] preparation of electrically conductive polyalkoxythiophenes [CA115: 50551u],

[0072] desulfuration of oil and effluent [CA 116: 261878q],

[0073] preparation of triglycidyltrimethylolalkane-based compositions[CA 117: 92344a],

[0074] preparation of polymers from styrene and carbon monoxide [CA 117:172290v],

[0075] preparation of organic salts for the storage of information [CA117: 17381g],

[0076] production of information carriers having good light resistance[CA 115: 267063w],

[0077] preparation of silicon support materials for catalysts [CA 117:74989k],

[0078] polymerisation of pyrrole derivatives [CA 117: 70577b],

[0079] copolymerisation of carbon monoxide and an olefinicallyunsaturated compound[CA 118: 7520h],

[0080] preparation of electrically conductive polymers [CA 118:137707k],

[0081] preparation of magnetic contrast agents [CA 118: 299355x],

[0082] preparation of polymer coatings [CA 119: 54608y],

[0083] removal of oxide layers on stainless steel [CA 119: 77272y],

[0084] synthesis of methyl tert-butyl ether [CA 119: 202992m],

[0085] preparation of cyclic sulfonium salts containing 5-7 carbons [CA119: 249826a],

[0086] preparation of cyclosiloxanes [120: 108008u],

[0087] refining of heavy oils and bitumen [CA 120: 195633k],

[0088] treatment of aluminium compounds [CA 120: 283104u],

[0089] preparation of quaternary pyridinium or anilinium salts [CA 121:9165g],

[0090] copolymerisation of olefins and carbon monoxide [CA 121: 10209f],

[0091] preparation of aromatic hydroxylic compounds [CA 121: 133684q],

[0092] preparation of acetic ester derivatives [CA 121: 157308w],

[0093] preparation of resin from dialkenylbenzene and polyarylamines [CA122: 70050c],

[0094] preparation of substituted pyrrolopyrimidin-4-ones [CA 122:314562q],

[0095] recovery of petroleum [CA 122: 295102w],

[0096] use as non-aqueous battery electrolytes [CA 122: 118595j],

[0097] preparation of stable methyl cations [CA 124: 288639q],

[0098] preparation of cyclic sulfonium salts [CA 125: 114470h],

[0099] preparation of optical storage materials [CA 125: 127895a],

[0100] preparation of conjugated fluoropyridinium salts [CA 125:119500c],

[0101] preparation of iridium/diphosphine complexes [CA 126: 226760e],

[0102] asymmetric hydrogenation of imines [CA 126: 225097g],

[0103] hydroformylation of unsaturated compounds [CA 126: 225032g],

[0104] synthesis of polymers [CA 126: 104554v],

[0105] preparation of polymers from polycycloolefins with silyl groups[CA 127: 110414m],

[0106] preparation of ruthenium catalysts [CA 127: 83071p],

[0107] preparation of ibuprofen [CA 127: 318741y],

[0108] preparation of cyclohexadienyl compounds [CA 126: 212225x],

[0109] copolymerisation of olefins [CA 126: 199931c],

[0110] preparation of inorganic methylimidazolinium salts [CA 128:167423p],

[0111] preparation of SiCO and SiC ceramic fibres [CA 128: 234151p],

[0112] preparation of thermoprint materials [CA 128: 210892e],

[0113] preparation of polymers [CA 129: 317091r],

[0114] preparation of aziridine-polyether compounds [CA 131: 35901 v],

[0115] preparation of dicarboxylic acid diesters [CA 131: 199417t],

[0116] hydroxylation of aromatic hydrocarbons [CA 129: 218223d],

[0117] preparation of carboxylic acids and carboxylic acid esters [CA129: 216347y],

[0118] pretreatment of lithographic printing plates [CA 129: 195815g].

[0119] The invention is explained below with reference to examples.These examples serve merely to explain the invention and do not restrictthe general inventive idea. The process according to the invention canbe used to prepare, for example,trifluoro-tris(perfluoroalkyl)phosphoric acids in virtually quantitativeyield by reaction of difluorotris(perfluoroalkyl)phosphoranes withhydrogen fluoride in suitable solvents. Surprisingly, this yield isvirtually unimpaired by hydrolysis.

[0120] The process according to the invention can be used, for example,to prepare a highly concentrated aqueous solution oftrifluorotris(pentafluoroethyl)phosphoric acid within a few minutes byreaction of difluorotris(pentafluoroethyl)phosphoranelwith 18.3% byweight aqueous HF. The reaction proceeds in accordance with the reactionequation [2]:

(C₂F₅)₃PF₂+HF+5 H₂O→[(C₂F₅)₃ ⁻H⁺5 H₂O  [2]

[0121] The resultant solution has a concentration of 83.2% by weight andis stable for a number of weeks at room temperature.

[0122] Acid concentrations of less than 83.2% by weight can also beprepared in this way, for example by dilution with a suitable solvent orby reaction of a phosphorane with more highly diluted hydrogen fluoridesolution.

[0123] However, the reaction of phosphoranes with more-dilute aqueoushydrogen fluoride solutions, for example 2% by weight, take more time.In the case of more highly diluted aqueous hydrogen fluoride solutions,firstly an adduct of water and phosphorane is formed, and this is thenslowly converted into the more stable product. The rate of conversion ofthe adduct into the product is temperature-dependent. At roomtemperature, the conversion in accordance with reaction [2] in 2% byweight hydrogen fluoride solution takes 2 days. At −21° C. and under thesame concentration ratios, only 30% of the adduct has converted intotrifluorotris(pentafluoroethyl)phos-phoric acid within six days.

[0124] On reaction of the phosphorane in an ice bath in accordance withreaction equation [2] with a 4.3% by weight aqueous hydrogen fluoridesolution, a mixture of phosphorane/water adduct andtrifluorotris(pentafluoroethyl)phosphoric acid in the ratio 1:2 isformed within 2-3 minutes.

[0125] The reaction can be carried out at atmospheric pressure orsuperatmospheric pressure, if desired also under a protective-gasatmosphere.

[0126] Trifluorotris(pentafluoroethyl)phosphoric acid can exist in twodifferent conformations, the meridional conformation and the facialconformation. The two structures exist in equilibrium. This equilibriumis dependent on the temperature and the hydrogen fluoride concentrationin water during reaction of the starting materials. Initially, themeridional structure is formed, which then achieves an equilibrium withthe facial structure.

[0127] The person skilled in the art understands that the proton in thestrong acids according to the invention is in the form of a complex withthe respective solvent. In the formulation of the formulae in theexamples, the complex of proton and solvent has therefore not beenformulated out.

[0128] The complete disclosure content of all applications, patents andpublications mentioned above and below and of the correspondingapplication DE 101 30 940.6, filed on Jun. 27, 2001, is incorporatedinto this application by way of reference.

[0129] Even without further comments, it is assumed that a personskilled in the art will be able to utilise the above description in thebroadest scope. The preferred embodiments and examples should thereforemerely be regarded as descriptive disclosure which is absolutely notlimiting in any way.

[0130] All NMR spectra were measured on a Bruker WP 80 SY spectrometer(¹H: 80 MHz, ¹⁹F: 75.47 MHz).

EXAMPLES Example 1

[0131] 3.74 g of water were added to 3.14 g of a 40% by weight aqueoushydrofluoric acid (62.8 mmol of HF) (in total 312.1 mmol of water) in anFEP (fluoroethylene polymer) flask. After this mixture had been cooledin an ice bath, 26.55 g (62.3 mmol) ofdifluorotris(pentafluoroethyl)phosphorane were added over the course of2 minutes while stirring using a magnetic stirrer. All the phosphoranehad dissolved within 3 minutes, and a colourless, clear solution ofaqueous acid [(C₂F₅)₃PF₃]⁻H⁺ had formed. 33.4 g of an 83.2% by weighttrifluorotris(pentafluoroethyl)phosphoric acid solution were prepared invirtually quantitative yield.

[0132] The compound conforms to the formula: [(C₂F₅)₃PF₃]⁻H⁺.5H₂O.

[0133] The solution was analysed by ¹⁹F NMR spectroscopy. The spectrawere measured using an FEP tube with an acetone-D₆ film as external lockand CCl₃F as external reference.

[0134]¹⁹F NMR, δ, ppm: −44.03 dm (PF); −80.61 m (CF₃); −82.47 m (2CF₃);−88.99 dm (PF₂); −115.36 dm (3CF₂); J¹ _(P,F)=889 Hz; J¹ _(P,F)=907 Hz;J²P, F=92 Hz.

[0135] These signals belong to the meridional structure of the acid[(C₂F₅)₃PF₃]⁻H⁺.5H₂O. Within 2 days, a new doublet formed in the ¹⁹F NMRspectrum at −67.41 ppm; J¹ _(P,F)=786 Hz (PF₃ group), which can beassigned to the facial structure of the acid [(C₂F₅)₃PF₃]⁻H⁺5H₂O. Nofurther changes were observed during storage at room temperature overthe next 3 weeks. The 83.2% by weight acid formed an equilibrium mixtureof about 90% of the meridional conformation and 10% of the facialconformation of the acid at room temperature.

Example 2

[0136] 2.24 g of water were added to 1.88 g of a 40% by weight aqueoushydrofluoric acid solution (37.6 mmol of HF) (in total 186.8 mmol ofwater) in an FEP flask. 15.88 g (37.3 mmol) ofdifluorotris(pentafluoroethyl)phosphorane were added to the aqueous HFsolution at room temperature over the course of 3 minutes while stirringthe reaction mixture using a magnetic stirrer. Due to the exothermicreaction, temperatures of up to 50° C. were reached, while thephosphorane dissolved. 20.0 g of a colourless, clear solution of[(C₂F₅)₃PF₃]⁻H⁺ in water with a concentration of 83.2% by weight wereformed in virtually quantitative yield.

[0137] The solution was analysed by ¹⁹F NMR spectroscopy. The spectrawere measured using an FEP tube with an acetone-D₆ film as external lockand CCl₃F as external reference.

[0138]¹⁹F NMR (meridional conformation), δ, ppm: −44.46 dm (PF); −81.05m (CF₃); −82.85 m (2CF₃); −89.54 dm (PF₂); −115.74 dm (3CF₂); J¹_(P,F)=889 Hz; J¹ _(P,F)=905 Hz; J² _(P,F)=93 Hz.

[0139]¹⁹F NMR (facial conformation), δ, ppm: −67.82 dm (PF₃); J¹_(P,F)=784 Hz. Other signals of the facial conformation overlapped withthe signals of the meridional conformation.

[0140] The spectra show that in this case both conformations of theacid, both the meridional and the facial conformation, are formed at thetime of preparation of the solution.

Example 3

[0141] 10.57 g of water were added to 3.91 g of a 40% by weight aqueoushydrofluoric acid solution (78.2 mmol of HF) (in total 716.8 mmol ofwater) in an FEP flask. After this mixture had been cooled in an icebath, 33.34 g (78.2 mmol) of difluorotris(penta-fluoroethyl)phosphoranewere added over the course of 3 minutes while stirring using a magneticstirrer. All the phosphorane dissolved within this time, and a clearsolution of [(C₂F₅)₃PF₃]⁻H⁺ was formed. 47.8 g of aqueoustrifluorotris(pentafluoroethyl)-phosphoric acid (I) in a concentrationof 73.0% by weight were obtained in quantitative yield.

[0142] hu 19F NMR (CCl₃F—external reference): −44.45 dm (PF); −80.84 m(CF₃); −82.57 m (2CF₃); −89.13 dm (PF₂); −115.75 dm (3CF₂); J¹_(P,F)=889 Hz; J¹ _(P,F)=909 Hz; J² _(P,F)=92 Hz.

[0143] The signals shown belong to the meridional structure of the acid[(C₂F₅)₃PF₃]⁻H⁺ and exhibited no changes in the spectrum within 5 days.The acid [(C₂F₅)₃PF₃]⁻H⁺ thus preferentially exhibits the meridionalconformation in the present concentration at room temperature.

Example 4

[0144] 12.46 g of water were added to 1.51 g of a 40% by weight aqueoushydrofluoric acid solution (30.2 mmol of HF) (in total 741.7 mmol ofwater) in an FEP flask. After this mixture had been cooled in an icebath, 12.74 g (29.9 mmol) of difluorotris(penta-fluoroethyl)phosphoranewere added over the course of 3 minutes while stirring using a magneticstirrer. All the phosphorane dissolved in this period, and 26.7 g of acolourless, clear solution of the acid were obtained in virtuallyquantitative yield.

[0145] The ¹⁹F NMR spectrum showed the presence of two forms ofhexacoordinated phosphorus. The first form is a complex ofdifluorotris(pentafluoroethyl)phosphorane with water:

[0146]¹⁹F NMR (CCl₃F—external reference): −80.39 m (CF₃); −81.31m(2CF₃); −89.19 dm (PF₂); −113.78 dm (3CF₂); −164.59 s (H₃O⁺HF) J¹_(P,F)=846 Hz ; J² _(P,F)=89 Hz.

[0147] The second form is the usual meridional conformation oftrifluorotris(pentafluoro-ethyl)phosphoric acid [(C₂F₅)₃PF₃]⁻H⁺.

[0148]¹⁹F NMR (CCl₃F—external reference): −44.60 dm (PF); −80.81 m(CF₃); −82.49 m (2CF₃); −89.34 dm (PF₂); −115.96 dm (3CF₂); J¹_(P,F)=889 Hz; J¹ _(P,F)=884 Hz; J² _(P,F)=95 Hz.

[0149] Within 4 days of storage at room temperature, the ¹⁹F NMRspectrum only showed the presence of the meridional conformation oftrifluorotris(pentafluoroethyl)phosphoric acid[(C₂F₅)₃PF₃]³¹H⁺ insolution.

Example 5

[0150] 29.60 g of water were added to 1.47 g of a 40% by weight aqueoushydrofluoric acid solution (29.4 mmol of HF) (in total 1691.6 mmol ofwater) in an FEP flask. After this mixture had been cooled in an icebath, 12.47 g (29.3 mmol) of difluorotris(pentafluoroethyl)phosphoranewere added over the course of three minutes while stirring using amagnetic stirrer. All the phosphorane dissolved within this period, anda colourless, clear solution of 43.5 g was prepared.

[0151] The ¹⁹F NMR spectrum showed that in this case principally theaqueous adduct is formed directly on addition of the phosphorane.

[0152]¹⁹F NMR (CCl₃F—external reference): −79.49 m (CF₃); −80.74 m(2CF₃); −88.60 dm (PF₂); −113.35 dm (3CF₂); −162.54 s (H₃O⁺.HF) J¹_(P,F)=842 Hz; −J² _(P,F)=89 Hz.

[0153] Within five days at room temperature, this adduct was convertedcompletely into tris(pentafluoroethyl)trifluorophosphoric acid[(C₂F₅)₃PF₃]⁻H⁺. This was confirmed by ¹⁹F NMR spectroscopy.

Example 6

[0154] 5.64 g (122.3 mmol) of dimethyl ether were cooled to −35° C. inan FEP flask using an ethanol bath. In succession, firstly 1.42 g (71.0mmol) of hydrogen fluoride (HF) were slowly added to the reactionmixture and subsequently 30.25 g (71.0 mmol) ofdifluorotris(pentafluoroethyl)phosphorane were added over the course offive minutes while the reaction mixture was stirred using a magneticstirrer. When the phosphorane had dissolved and the reaction mixture hadwarmed to room temperature, 37.3 g of a colourless, clear solution wereobtained.

[0155] This solution was analysed by ¹⁹F NMR spectroscopy. The spectrawere measured using an FEP tube with an acetonitrile-D₃ film as externallock and CCl₃F as internal reference.

[0156] The ¹⁹F NMR spectrum showed that in this case the acid[(C₂F₅)₃PF₃]⁻H⁺ is preferentially formed with the meridional structure.

[0157]¹⁹F NMR of the meridional conformation: −43.58 dm (PF); −80.19 m(CF₃); −81.90 m (2CF₃); −87.03 dm (PF₂); −115.51 dm (3CF₂); J¹P,F=888Hz; J¹ _(P,F)=894 Hz; J² _(P,F)=94 Hz.

[0158] Within three days, the concentration of the facial conformationof the acid [(C₂F₅)₃PF₃]⁻H⁺ in the mixture increased.

[0159]¹⁹F NMR spectrum of the facial conformation: −66.12 dm; J¹_(P,F)=798 Hz (PF₃ group).

[0160] Other signals of the facial conformation overlapped with thesignals of the meridional conformation.

[0161] No further changes in the ¹⁹F NMR spectra were observed withinfive weeks during storage at room temperature.

Example 7

[0162] 6.04 g (81.5 mmol) of dry diethyl ether in an FEP flask werecooled by means of an ice bath. While stirring using a magnetic stirrer,firstly 0.92 g (45.9 mmol) of hydrogen fluoride (HF) was slowly added tothe diethyl ether and then 18.67 g (43.8 mmol) ofdifluorotris(pentafluoroethyl)phosphorane were added over the course of5 minutes. After dissolution of the phosphorane within one to twominutes and warming of the reaction mixture to room temperature, 25.6 gof a colourless, clear solution were formed.

[0163] This solution was analysed by ¹⁹F NMR spectroscopy. The spectrawere measured using an FEP tube with an acetonitrile-D₃ film as externallock and CCl₃F as internal reference.

[0164] The ¹⁹F NMR spectrum showed that the acid [(C₂F₅)₃PF₃]⁻H⁺ isformed in two conformations.

[0165]¹⁹F NMR of the meridional conformation (approximately 85 mol %):−43.68 dm (PF); −80.00 m (CF₃); −81.71 m (2CF₃); −86.93 dm (PF₂);−115.31 dm (3CF₂); J¹ _(P,F)=890 Hz; J^(P,F)=897 Hz; J² _(P,F)=92 Hz.

[0166]¹⁹F NMR spectrum of the facial form (approximately 15 mol %):−67.37 dm; J¹ _(P,F)=793 Hz (PF₃ group). Other signals of the facialconformation overlapped with the signals of the meridional conformation.

[0167] No changes in the ¹⁹F NMR spectrum were observed within twomonths on storage at room temperature.

Example 8

[0168] 3.33 g (103.9 mmol) of methanol in an FEP flask were cooled usingan ice bath. While stirring using a magnetic stirrer, firstly 0.91 g(45.5 mmol) of hydrogen fluoride (HF) was slowly added to the methanoland 18.05 g (42.4 mmol) of difluorotris(pentafluoroethyl)phosphoranewere added to the reaction mixture over the course of a further fiveminutes. After dissolution of the phosphorane and warming of thereaction mixture to room temperature, 22.2 g of a colourless, clearsolution were obtained.

[0169] This solution was analysed by ¹⁹F NMR spectroscopy. The spectrawere measured using an FEP tube with an acetonitrile-D₃ film as externallock and CCl₃F as internal reference.

[0170] The ¹⁹F NMR shows that in this case the acid [(C₂F₅)₃PF₃]⁻H⁺ isformed in two conformations.

[0171]¹⁹F NMR of the meridional conformation (approximately 85 mol %):−43.80 dm (PF); −80.50 m (CF₃); −81.93 m (2CF₃); −87.50 dm (PF₂);−114.93 dm (3CF₂); J¹ _(P,F)=887 Hz; J² _(P,F)=95 Hz.

[0172]¹⁹F NMR spectrum of the facial conformation (approximately 15 mol%): −66.44 dm; J¹ _(P,F)=780 Hz. (PF₃ group). Other signals of thefacial form overlapped with the signals of the meridional form.

[0173] No changes in the ¹⁹F NMR spectrum were observed within one monthon storage at room temperature.

Example 9

[0174] 3.02 g (48.8 mmol) of dimethyl sulfide (CH₃)₂S in an FEP flaskwere cooled by means of an ice bath. While stirring using a magneticstirrer, firstly 0.98 g (49.0 mmol) of hydrogen fluoride (HF) andsubsequently, over the course of five minutes, 20.88 g (49.0 mmol) ofdifluorotris(pentafluoroethyl)phosphorane were added to the dimethylsulfide. When all the phosphorane had been added, the reaction mixturehardened completely. After additional mechanical stirring and drying ofthe reaction mixture at room temperature in a stream of argon protectivegas, 23.9 g of a colourless, solid material were obtained.

[0175] 0.4 g of this material was dissolved in acetonitrile-D₃, and thissolution was analysed by ¹⁹F NMR spectroscopy. CCl₃F was used asinternal reference.

[0176] The ¹⁹F NMR spectrum showed that in this case the acid[(C₂F₅)₃PF₃]⁻H⁺ is formed in the meridional conformation.

[0177]¹⁹F NMR: 43.54 dm (PF); −79.66 m (CF₃); −81.25 m (2CF₃); −86.83 dm(PF₂); −115.28 dm (3CF₂); J¹ _(P,F)=889 Hz; J¹, F=906 Hz; J² _(P,F)=92Hz.

Example 10

[0178] 3.23 g (12.3 mmol) of triphenylphosphine (Ph₃P) in an FEP flaskwere cooled to −25° C. in an ethanol/dry ice bath. While the reactionmixture was stirred using a magnetic stirrer, firstly 0.66 g (33.0 mmol)of hydrogen fluoride (HF) was slowly added to the triphenylphosphine andthen 5.25 g (12.3 mmol) of difluorotris(pentafluoroethyl)-phosphoranewere added over the course of a further five minutes. When all thephosphorane had been added, the reaction mixture hardened completely.After additional mechanical mixing and drying of the reaction mixture atroom temperature under a stream of argon protective gas, 8.8 g of apale-yellow solid were obtained. 0.4 g of this material was dissolved inacetonitrile-D₃, and this solution was analysed by ¹⁹F NMR spectroscopy.CCl₃F was used as internal reference.

[0179] The ¹⁹F NMR spectrum showed that in this case the acid[(C₂F₅)₃PF₃]⁻H⁺ as a complexes with triphenylphosphine is formed in themeridional conformation.

[0180]¹⁹F NMR: −43.65 dm (PF); −79.75 m (CF₃); −81.34 m (2CF₃); −86.99dm (PF₂); −115.45 dm (3CF₂); J¹P, F=889 Hz; J¹ _(P,F)=906 Hz; J²_(P,F)=92 Hz.

[0181] A small signal of residual HF is visible in the ¹⁹F NMR spectrum(−181.75 ppm). ¹H NMR: 7.8 m (Ph₃PH⁺)

Example 11

[0182] 1.71 g (23.4 mmol) of dimethylformamide, HC(O)N(CH₃)₂, in an FEPflask were cooled to −25° C. using an ethanol/dry ice bath. Whilestirring using a magnetic stirrer, firstly 0.566 g (28.3 mmol) ofhydrogen fluoride (HF) was slowly added to the dimethylformamide andthen 9.92 g (23.3 mmol) of difluorotris(pentafluoroethyl)-phosphoranewere added at 0° C. over the course of five minutes. When all thephosphorane had been added, the reaction mixture was warmed to roomtemperature. 12.2 g of a high-density, virtually solid, white materialwere produced.

[0183] Small amounts of this material were dissolved indimethylformamide and in acetonitrile-D₃, and these solutions wereanalysed by ¹⁹F and ¹H NMR spectroscopy. CCl₃F and TMS were used asinternal reference.

[0184] The ¹⁹F NMR spectrum showed that in this case the acid[(C₂F₅)₃PF₃]⁻H⁺ is formed in the meridional conformation.

[0185]¹⁹F NMR (solvent: acetonitrile-D₃): −43.64 dm (PF); −79.76 m(CF₃); −81.35 m (2CF₃); −87.08 dm (PF₂); −115.35 dm (3CF₂); J¹_(P,F)=889 Hz; J¹ _(P,F)=906 Hz; J² _(P,F)=90 Hz.

[0186] A small signal of residual hydrogen fluoride was again observedin the ¹⁹F NMR spectrum (−182.30 ppm).

[0187]¹H NMR (solvent: acetonitrile-D₃): 3.12 s (CH₃); 3.27 s (CH₃);8.19 s (CH); 10.97 s (H⁺).

[0188]¹⁹F NMR (solvent: dimethylformamide): −43.88 dm (PF); −79.76 m(CF3); −81.35 m (2CF₃); −87.08 dm (PF₂); −115.35 dm (3CF₂); J¹_(P,F)=889 Hz J¹ _(P,F)=906 Hz; J² _(P,F)=90 Hz.

[0189] A small signal of residual hydrogen fluoride was again observedin the ¹⁹F NMR spectrum (−182.30 ppm).

Example 12

[0190] 4.92 g (81.9 mmol) of acetic acid, CH₃COOH, in an FEP flask werecooled by means of an ice bath. While stirring using a magnetic stirrer,firstly 0.424 g (21.2 mmol) of hydrogen fluoride (HF) was slowly addedto the acetic acid and then 8.83 g (20.7 mmol) ofdifluorotris(pentafluoroethyl)phosphorane were added over the course offive minutes. After the phosphorane had dissolved and the reactionmixture had been warmed to room temperature, 14.17 g of a colourless,clear solution were obtained.

[0191] This solution was analysed by ¹⁹F NMR spectroscopy. The spectrawere measured using an FEP tube with an acetone-D₆ film as external lockand CCl₃F as external reference. In this example, the ¹⁹F NMR spectrumshows that the acid [(C₂F₅)₃PF₃]⁻H⁺ is preferentially formed in themeridional structure.

[0192]¹⁹F NMR of the meridional form: −44.65 dm (PF); −80.94 m (CF₃);−82.58 m (2CF₃); −88.59 dm (PF₂); −116.16 dm (3CF₂); J¹ _(P,F)=890 Hz;J² _(P,F) =92 Hz.

[0193]¹H NMR (acetonitrile-D₃ film): 2.43 s (CH₃); 12.43 s (H⁺).

Example 13

[0194] 0.077 g of a 40% by weight aqueous hydrofluoric acid solution(1.54 mmol of HF) was mixed with 0.124 g of water (in total 9.44 mmol ofwater) in an FEP flask. While stirring using a magnetic stirrer, thismixture was cooled in an ice bath, and 0.836 g (1.15 mmol) ofdifluorotris(nonafluoro-n-butyl)phosphorane was added over the course oftwo minutes. All the phosphorane had dissolved within a further fiveminutes, and a colourless, clear solution of [(C₄F₉)₃PF₃]⁻H⁺ in waterhad formed. 1.037 g of this solution oftrifluorotris(nonafluoro-n-butyl)phosphoric acid having a concentrationof 83.6% by weight in water were obtained in virtually quantitativeyield.

[0195] The solution was analysed by ¹⁹F NMR spectroscopy. The spectrawere measured using an FEP tube with an acetone-D₆ film as external lockand CCl₃F as external reference.

[0196]¹⁹F NMR, δ, tpm: −44.91 dm (PF); −82.47 m (3CF₃); −87.29 dm (PF₂);

[0197] −112.32 m (3CF₂); −120.15 m (1CF₂); −122.52 m (2CF₂); −126.24 m(3CF₂); J¹ _(P,F)=904 Hz; JP¹ _(P,F)=929 Hz.

Example 14

[0198] 0.272 g (3.67 mmol) of dried diethyl ether in an FEP flask wascooled using an ice bath. While stirring using a magnetic stirrer,firstly 0.043 g (2.15 mmol) of hydrogen fluoride (HF) was slowly addedto the diethyl ether and then 0.864 g (1.19 mmol) ofdifluorotris(nonafluoro-n-butyl)phosphorane was added over the course offive minutes. During the addition, all the phosphorane dissolved, and1.17 g of a colourless, clear solution were prepared.

[0199] The solution was analysed by ¹⁹F NMR spectroscopy. The spectrawere measured using an FEP tube with an acetonitrile-d₆ film as externallock and CCl₃F as internal reference.

[0200] The ¹⁹F NMR spectrum confirmed that the acid [(C₄F₉)₃PF₃]⁻H⁺(III) is formed.

[0201]¹⁹F NMR, δ, ppm: −44.17 dm (PF); −81.37 m (3CF₃); −84.76 dm (PF₂);−112.00 m (3CF₂); −119.18 m (1CF₂); −121.32 m (2CF₂); −125.15 m (3CF₂);J¹ _(P,F)=907 Hz; J¹ _(P,F)=939 Hz.

Example 15

[0202] 0.68 g of an 18.3% by weight aqueous hydrofluoric acid solution(6.22 mmol of HF) was slowly added at 0° C. to 3.27 g (6.22 mmol) oftrifluorobis(nonafluoro-n-butyl)-phosphorane while stirring using amagnetic stirrer. All the phosphorane had dissolved within threeminutes, and a colourless, clear solution of H⁺[(n-C₄F₉)₂PF₄]⁻ in waterformed. The yield was 3.95 g of a solution oftetrafluorobis(nonafluoro-n-butyl)phosphoric acid having a concentrationof 85.9% by weight in water in virtually quantitative yield. The productconforms to the formula H⁺[(C₄F₉)₂PF₄]⁻.5H₂O. The solution was analysedby ¹⁹F NMR spectroscopy. The spectra were recorded using an FEP sampletube inside an NMR tube having a 5 mm thick wall, with an acetone-D₆film being used as external lock and CCl₃F in the film as reference.

[0203]¹⁹F NMR spectrum, δ, ppm: −70.72 dm (PF₄); −81.19t (2CF₃); −115.15dm (2CF₂); −122.58 m (2CF₂); −124.77 t (2CF₂); J¹ _(P,F)=958 Hz; J²_(P,F)=105 Hz; J⁴ _(F,F)=9.3 Hz; J⁴ _(F,F)=16.4 Hz;

Example 16

[0204] 0.713 g (1.67 mmol) oftrifluorobis(heptafluoro-i-propyl)phosphorane was slowly added (over thecourse of 2 minutes) at 0° C. to 0.217 g of a 20.8% by weight, aqueoushydrofluoric acid solution (2.26 mmol of HF) while stirring using amagnetic stirrer. During this time, all the phosphorane dissolved, and acolourless, clear solution oftetrafluorobis(heptafluoro-i-propyl)phosphoric acid, H^(+[(i-C)₃F₇)₂PF₄]⁻, in water formed.

[0205] The solution was analysed by ¹⁹F NMR spectroscopy. The spectrawere recorded using an FEP sample tube inside an NMR tube having a 5 mmthick wall, with an acetone-D6 film being used as external lock andCCl₃F in the film as reference. ¹⁹F NMR spectrum, δ, ppm: −58.37 dm(PF₄); −71.23 m (4CF₃); −182.72 dm (2CF); J¹ _(P,F)=955 Hz; J⁴_(P,F)=78.4 Hz.

[0206] The signal of the excess HF was measured at 168.89 ppm in the ¹⁹FNMR spectrum.

Example 17

[0207] 6.57 g (36.7 mmol) of triethylene glycol dimethyl ether(triglyme) in an FEP flask were cooled by means of an ice bath. Firstly0.74 g (37.0 mmol) of hydrogen fluoride (HF) was slowly added to thetriglyme and then, over the course of five minutes, a further 14.90 g(35.0 mmol) of difluorotris(pentafluoroethyl)phosphorane were addedwhile stirring the reaction mixture using the magnetic stirrer. Afterthe reaction mixture had been stirred for a further hour at roomtemperature, 22.19 g of a yellow-brown, very viscous substance wereobtained. Small amounts of this material were diluted withdichloromethane, and this solution was analysed by ¹⁹F NMR spectroscopy.The spectra were recorded using an FEP sample tube inside a 5 mm NMRtube with an acetone-D₆ film as external lock and CCl₃F as internalreference.

[0208] The ¹⁹F NMR spectrum shows that in this case one mole of the acidH⁺[(C₂F₅)₃PF₃]⁻ are formed per mole of triglyme.

[0209]¹⁹F NMR spectrum of the meridionial form (approx. 90%): −44.41 dm(PF); −80.35 m (CF₃); −82.00 m (2CF₃); −87.94 dm (PF₂); −115.87 dm(3CF₂); J¹ _(P,F)=890 Hz; J¹ _(P,F)=891 Hz; J¹ _(P,F)=90 Hz.

[0210]¹⁹F NMR spectrum of the facial form (approx. 10%): −68.29 dm; J¹_(P,F)=794 Hz (PF₃ group).

[0211] Some signals of the facial form overlap with those of themeridional form.

Example 18

[0212] 6.78 g (16.9 mmol) of polyethylene glycol 400 (PEG 400) wereintroduced into an FEP flask and cooled using an ice bath. Whilestirring using the magnetic stirrer, firstly 0.79 g (39.5 mmol) ofhydrogen fluoride (HF) was slowly added to the PEG 400 and then afurther 15.27 g (35.8 mmol) of difluorotris(pentafluoroethyl)phosphoranewere added over the course of three minutes. After this reaction mixturehad been stirred at room temperature for 10 hours, 21.8 g of ayellow-brown, dense, gelatinous material were obtained. Small amounts ofthis material were diluted with dichloromethane, and the solution wasanalysed by ¹⁹F NMR spectroscopy. The spectra were recorded using an FEPsample tube inside a 5 mm NMR tube with an acetone-D₆ film as externallock and CCl₃F as internal reference.

[0213] The ¹⁹F NMR spectrum shows that in this case the acidH⁺[(C₂F₅)₃PF₃]⁻ was formed in a polymeric matrix, approximately 2 mol ofacid per mole of polyethylene glycol 400.

[0214]¹⁹F NMR spectrum of the meridional form (approx. 80%): −44.64 dm(PF); −80.48 m (CF₃); −82.07 m (2CF₃); −88.00 dm (PF₂); −115.94 dm(3CF₂); J¹ _(P,F)=889 Hz; J¹ _(P,F)=894 Hz; J² _(P,F)=95 Hz.

[0215]¹⁹F NMR spectrum of the facial form (approx. 20%): −68.16 dm; J¹_(P,F)=788 Hz (PF₃ group).

[0216] Other signals of the facial form overlapped with those of themeridional form.

Example 19

[0217] The starting material,difluorotris(pentafluorophenyl)phosphorane, was prepared as follows:0.711 g (1.34 mmol) of tris(pentafluorophenyl)phosphine in 5 cm³ of drytoluene was mixed with 0.300 g (1.77 mmol) of xenon difluoride. The gaswas liberated by heating the reaction mixture to from 50 to 60° C. Thereaction was complete within 20 minutes. After the solvent had beenevaporated under reduced pressure, 0.750 g of a white, solid substancewas isolated. The yield of thedifluorotris(pentafluoro-phenyl)phosphorane was 98.5 mol %. The ¹⁹F NMRspectrum of the compound agrees with the spectra known from theliterature (M. Fild and R. Schmutzler, J. Chem. Soc. (A), 1969, pp.840-843).

[0218] 0.50 g of dried diethyl ether and 0.107 g (0.187 mmol) ofdifluorotris(pentafluoro-phenyl)phosphorane in an FEP flask were cooledby means of an ice bath. Firstly 0.050 g (2.5 mmol) of hydrogenfluoride, HF, and then, over the course of two minutes, 0.3 g oftriethylamine were added while the reaction mixture was stirred usingthe magnetic stirrer. During the addition, all the phosphoranedissolved, and triethylammonium hydrofluoride precipitated. After thesediment had been separated off and the solvent had been evaporatedunder reduced pressure 0.13 g of a viscous substance was isolated. Smallamounts of this material were dissolved in acetone-D₆, and this solutionwas analysed by ¹⁹F and ¹H NMR spectroscopy. The spectrum confirmed theformation of trifluorotris(pentafluorophenyl)phosphoric acid,[(C₆F₅)₃PF₃]⁻H⁺, as a complex with triethylamine.

[0219]¹⁹F NMR spectrum (solvent: acetone-D₆; reference: CCl₃F,internal), δ, ppm: −6.73 dm (PF); −39.71 dm (PF₂); −132.06 m (4F);−134.75 m (2F); −160.42 t (1F); −161.24 t (2F); −166.20 m (6F); J¹_(P,F)=811 Hz; J¹ _(P,F)=797 Hz; J³ _(F, F)=20 Hz.

[0220]¹H NMR spectrum (solvent: acetone-D₆; reference: TMS, internal),δ, ppm: 1.27 t (3CH₃), 3.04 q (3CH₂), 12.11 s (NH⁺); J³ _(H,H)=7.3 Hz.

Example 20

[0221] 6.36 g (70.6 mmol) of dry dimethyl carbonate, (CH₃O)₂CO, in anFEP flask were cooled using an ice bath. Firstly 10.99 g (25.8 mmol) ofdifluorotris(pentafluoro-ethyl)phosphorane were slowly added to thedimethyl carbonate and then 0.615 g (30.7 mmol) of hydrogen fluoride(HF) was added to the reaction mixture over the course of 5 minuteswhile stirring using a magnetic stirrer. After the phosphorane haddissolved and the reaction mixture had been warmed to room temperature,17.8 g of a colourless, clear solution were obtained.

[0222] The solution was analysed by ¹⁹F NMR spectroscopy. The spectrawere recorded using an FEP sample tube inside a 5 mm NMR tube with anacetone-D₆ film as external lock and CCl₃F as internal reference.

[0223] The ¹⁹F NMR spectrum shows that in this case the meridionalstructure of the acid [(C₂F₅)₃PF₃]⁻H⁺ is formed.

[0224]¹⁹F NMR spectrum: −44.34 dm (PF); −80.26 m (CF₃); −81.93 m (2CF₃);−87.78 dm (PF₂); −115.85 dm (3CF₂); J¹ _(P,F)=889 Hz; J¹ _(P,F)=92 Hz.

[0225]¹H NMR spectrum (acetone-D₃ film, standard: TMS): 4.49 s (CH₃);17.54 s (H⁺).

Applications of Trifluorotris(perfluoroalkyl)phosphoric Acids Example 21

[0226] 12.15 g of an 83.2% by weight, aqueoustrifluorotris(pentafluoroethyl)phosphoric acid (prepared as described inExample 1) were neutralised at 0° C. with stirring by addition of 0.95 glithium hydroxide monohydrate in small portions. 13.1 g of a clearsolution of lithium trifluorotris(pentafluoroethyl) phosphate having aconcentration of 78.2% by weight in water were obtained. The yield ofthe lithium trifluorotris(pentafluoroethyl)phosphate was virtuallyquantitative. The solution was analysed by ¹⁹F NMR spectroscopy. Thespectra were recorded using an FEP sample tube inside a 5 mm NMR tubewith an acetone-D₆ film as external lock and CCl₃F in the film asreference.

[0227]¹⁹F NMR spectrum, δ, ppm: −43.48 dm (PF); −79.54 m (CF₃); −81.30 m(2CF₃); −88.07 dm (PF₂); −114.21 dm (3CF₂); J¹ _(P,F)=891 Hz; J¹_(P,F)=908 Hz; J² _(P,F)=92 Hz.

Example 22

[0228] 20.44 g of an 83.2% by weight, aqueoustrifluorotris(pentafluoroethyl)phosphoric acid (prepared as described inExample 1) were neutralised by addition of 1.42 g of lithium carbonatein small portions with stirring. The yield was 21.0 g of a clearsolution of lithium trifluorotris(pentafluoroethyl) phosphate in aconcentration of 82.0% by weight in water. The yield of the lithiumtrifluotris(pentafluroethyl) phosphate was virtually quantitative. Thesolution was analysed by ¹⁹F NMR spectroscopy. The spectra were recordedusing an FEP sample tube inside a 5 mm NMR tube with an acetone-D₆ filmas external lock and CCl₃F in the film as reference.

[0229]¹⁹F NMR spectrum, δ, ppm: −43.31 dm (PF); −79.44 m (CF₃); −81.19 m(2CF₃); −87.96 dm (PF₂); −114.20 dm (3CF₂); J¹ _(P,F)=891 Hz; J¹_(P,F)=907 Hz; J² _(P,F)=92 Hz.

Example 23

[0230] A solution of 6.38 g (14.3 mmol) oftrifluorotris(pentafluoroethyl)phosphoric acid in 1.9 g of diethyl ether(prepared analogously to the process in Example 7) was neutralised byslow addition of 6.0 cm³ (15.0 mmol) of a 2.5 M solution of butyllithiumin hexane at 0° C. with stirring. The mixture was stirred for a furtherhalf an hour, and the complex of lithiumtrifluorotris(pentafluoroethyl)phosphate with diethyl ether (bottom,pale-yellow, viscous layer) was separated off from the hexane (upperlayer).

[0231] The ¹⁹F NMR spectrum of the diethyl ether solution showed thepresence of lithium trifluorotris(pentafluoroethyl)phosphate, which wasobtained in virtually quantitative yield. The spectra were recordedusing an FEP sample tube inside a 5 mm NMR tube with an acetone-D₆ filmas external lock and CCl₃F in the film as reference.

[0232]¹⁹F NMR spectrum of the meridional form (approx. 85 mol %): −47.19dm (PF); −79.80 m (CF₃); −81.34 m (2CF₃); −88.77 dm (PF₂); −114.84 dm(3CF₂); J¹ _(P,F)=867 Hz; J¹ _(P,F)=905 Hz; J² _(P,F)=92 Hz.

[0233]¹⁹F NMR spectrum of the facial form (approx. 15 mol %): −66.88 dm;J¹ _(P,F)=776 Hz (PF₃ group).

[0234] Other signals of the facial form overlapped with those of themeridional form.

Example 24

[0235] 10.77 g of an 83.2% by weight, aqueoustrifluorotris(pentafluoroethyl)phosphoric acid (prepared as described inExample 1) were diluted with 10 cm³ of water and neutralised with 1.52 gof magnesium hydroxycarbonate (Merck, proportion of the Mg cation atleast 24%) in small portions with cooling in an ice bath and withstirring. The excess magnesium hydroxycarbonate was filtered off, andthe solution of the magnesium trifluorotris(pentafluoroethyl)phosphatein water was analysed by ¹⁹F NMR spectroscopy. The spectra were recordedusing an FEP sample tube inside a 5 mm NMR tube with an acetone-D₆ filmas external lock and CCl₃F in the film as reference.

[0236]¹⁹F NMR spectrum, δ, ppm: −43.34 dm (PF); −79.35 m (CF₃); −80.99 m(2CF₃), −88.11 dm (PF₂); −114.54 dm (3CF₂); J¹ _(P,F)=874 Hz; J¹_(P,F)=899 Hz; J² _(P,F)=91 Hz.

Example 25

[0237] 7.19 g of an 83.2% by weight, aqueoustrifluorotris(pentafluoroethyl)phosphoric acid (prepared as described inExample 1) were diluted with 10 cm³ of water with cooling in an ice bathand with stirring and neutralised by addition of 1.76 g of zinchydroxycarbonate (Fluka, proportion of Zn cation≧58%) in small portions.The excess zinc hydroxycarbonate was filtered off, and the solution ofzinc trifluorotris(pentafluoro-ethyl)phosphate in water was analysed by¹⁹F NMR spectroscopy. The spectra were recorded using an FEP sample tubeinside a 5 mm NMR tube with an acetone-D₆ film as external lock andCCl₃F in the film as reference.

[0238]¹⁹F NMR spectrum, δ, ppm: −43.40 dm (PF); −79.56 m (CF₃); −81.23 m(2CF₃); −87.91 dm (PF₂); −114.45 dm (3CF₂); J¹ _(P,F)=890 Hz; J¹_(P,F)=913 Hz; J² _(P,F)=96 Hz.

Example 26

[0239] 10.78 g of an 83.2% by weight, aqueoustrifluorotris(pentafluoroethyl)phosphoric acid (prepared as described inExample 1) were diluted with 10 cm³ of water in an ice bath withstirring and neutralised with 2.78 g of copper(II) hydroxycarbonate insmall portions. The excess copper hydroxycarbonate was filtered off, andthe solution of copper trifluorotris(pentafluoroethyl)phosphate in waterwas analysed by ¹⁹F NMR spectroscopy. The spectra were recorded using anFEP sample tube inside a 5 mm NMR tube with an acetone-D₆ film asexternal lock and CCl₃F in the film as reference.

[0240]¹⁹F NMR spectrum of the meridional form, δ, ppm: −47.88 dm (PF);−84.03 m (CF₃); −85.59 m (2CF₃); −92.70 dm (PF₂); −119.27 dm (3CF₂); J¹_(P,F)=895 Hz; J² _(P,F)=87 Hz.

[0241] The small signal of the facial form of the copper salt was alsopresent in the spectrum: −71.44 d (PF₃); J¹ _(P,F)=790 Hz.

Example 27

[0242] 3.10 g of a 73.0% by weight, aqueoustrifluorotris(pentafluoroethyl)phosphoric acid (prepared as described inExample 3) were diluted with 5 cm³ of water with cooling in a water bathand with stirring and neutralised with 0.74 g of silver carbonate insmall portions. The excess silver carbonate was filtered off, and thesolution of silver trifluorotris(pentafluoroethyl) phosphate in waterwas analysed by ¹⁹F NMR spectroscopy. The spectra were recorded using anFEP sample tube inside a 5 mm NMR tube with an acetone-D₆ film asexternal lock and CCl₃F in the film as reference. ¹⁹F NMR spectrum, δ,ppm: −42.60 dm (PF); −78.66 m (CF₃); −80.35 m (2CF₃); −87.41 dm (PF₂);−114.06 dm (3CF₂); J¹ _(P,F)=890 Hz; J² _(P,F)=92 Hz.

Example 28

[0243] A solution of 16.68 g (37.4 mmol) oftrifluorotris(pentafluoroethyl)phosphoric acid in 14.52 g of diethylether (prepared as described in Example 7) was slowly added at roomtemperature with stirring to 20.50 g of a 50% by weight solution oftetra-(n-butyl)phosphonium chloride (10.25 g or 34.8 mmol) in toluene.The mixture was stirred for a further 30 minutes, and the solventmixture was distilled off at a reduced pressure of 13.3 Pa. 24.46 g of awhite, solid substance were obtained in this way.

[0244] The yield of tetra(n-butyl)phosphoniumtrifluorotris(pentafluoroethyl)phosphate was virtually quantitative. Themelting point after crystallisation from a methanol/water mixture was73-74° C.

[0245] Analysis: C 37.31%, H 5.06%; calculated: 37.51%, H 5.15%.

[0246]¹⁹F NMR spectrum (solvent: acetone-D₆; reference: CCl₃F internal):−43.83 dm (PF); −79.72 m (CF₃); −81.23 m (2CF₃); −86.77 dm (PF₂);−115.43 dm (3CF₂); J¹ _(P,F)=890 Hz; J¹ _(P,F)=905 Hz; J² _(P,F)=92 Hz.

[0247]¹H NMR spectrum (solvent, acetone-D₆; reference: TMS internal):0.95 t (4CH₃), 1.57 m (8CH₂), 2.34 m (4CH₂).

Example 29

[0248] 11.37 g of a 20% by weight, aqueous solution oftetraethylammonium hydroxide were slowly added (over the course of 2minutes) with stirring and cooling in an ice bath to 8.28 g of an 83.2%by weight aqueous trifluorotris(pentafluoroethyl)phosphoric acid(prepared as described in Example 1). The reaction mixture was dilutedwith 100 cm³ of water and stirred at room temperature for a further 10minutes. A white sediment was filtered off and washed twice with 30 cm³of water. After drying overnight in air, 8.55 of a white, solid materialwere obtained. The yield of tetraethylammoniumtrifluorotris(pentafluoroethyl)phosphate was 96.3%. Analysis: C 29.14%,H 3.40%, N 2.49%; calculated: C 29.23%, H 3.50%, N 2.43%. The meltingpoint after crystallisation of this product from a methanol/watermixture was unchanged at 95° C.

[0249]¹⁹F NMR spectrum (solvent: acetone-D₆; reference: CCl₃F internal):−43.78 dm (PF); −79.69 m (CF₃); −81.24 m (2CF₃); −86.80 dm (PF₂);−115.36 dm (3CF₂); J¹ _(P,F)=889 Hz; J¹ _(P,F)=906 Hz; J² _(P,F)=89 Hz.

[0250]¹H NMR spectrum (solvent: acetone-D₆; reference: TMS internal):1.39 tm (4CH₃), 3.48 q (4CH₂); J³ _(H,H)=7.3 Hz.

Example 30

[0251] 10.85 g of a 73.0% by weight, aqueoustrifluorotris(pentafluoroethyl)phosphoric acid (prepared as described inExample 3) were added slowly over the course of 3 minutes with stirringand cooling in an ice-water bath to 81.47 g of aqueoustetramethyl-ammonium hydroxide (prepared from 6.47 g of a 25% by weightaqueous (CH₃)₄N⁺⁻OH by dilution with 75 cm³ of water). The reactionmixture was stirred at room temperature for a further 10 minutes. Awhite sediment was filtered off and washed three times with 30 cm³ ofwater. After drying overnight in air, 8.55 g of a white, solid materialwere obtained. The yield of tetramethylammoniumtrifluorotris-(pentafluoroethyl)phosphate was 95.2%. The melting pointwas 112° C.

[0252]¹⁹F NMR spectrum (solvent: acetone-D₆; reference: CCl₃F internal):−43.70 dm (PF); −79.70 m (CF₃); −81.24 m (2CF₃); −86.75 dm (PF₂);−115.43 dm (3CF₂); J¹ _(P,F)=889 Hz; J¹ _(P,F)=909 Hz; J² _(P,F)=88 Hz.

[0253]¹H NMR spectrum (solvent: acetone-D₆; reference: TMS internal):3.42 s (4CH₃).

Example 31

[0254] 3.95 g of an 85.9% by weight aqueoustetrafluorobis(nonafluoro-n-butyl)phosphoric acid (prepared as describedin Example 15) were slowly added over the course of 3 minutes to 54.58 gof aqueous tetraethylammonium hydroxide (prepared from 4.58 g of a 20%by weight, aqueous (C₂H₅)₄N⁺⁻OH solution by dilution with 50 cm³ ofwater) with stirring and with cooling of the reaction mixture in an icebath. The reaction mixture was stirred at room temperature for a further10 minutes. A white sediment was filtered off and washed twice with 10cm³ of water. After drying overnight in air, 3.05 g of a white, solidmaterial were obtained. The yield of tetraethylammoniumtetrafluorobis(nonafluoro-n-butyl)phosphate was 72.6%.

[0255]¹⁹F NMR spectrum (solvent: acetone-D₆; reference: CCl₃F internal):−70.20 dm (PF₄); −80.87 m (2CF₃); −116.04 dm (2CF₂); −122.34 m (2CF₂);−124.61 t (2CF₂); J¹ _(P,F)=930 Hz; J² _(P,F)=94 Hz; J⁴ _(P,F)=15.7 Hz.

[0256]¹H NMR spectrum (solvent: acetone-D₆; reference: TMS internal):1.38 tm (4CH₃), 3.48 q (4CH₂); J³ _(H,H)=7.3 Hz.

Example 32

[0257] 0.030 g of lithium powder was added in small portions at roomtemperature and with stirring using a magnetic stirrer to 1.72 g of asolution of trifluorotris(pentafluoroethyl)phosphoric acid in dimethylcarbonate, prepared as described in Example 20. At the beginning, thereaction mixture reacted vigorously with evolution of hydrogen. Completereaction of the reaction components was achieved by warming the reactionmixture to 60° C. over a period of 30 minutes.

[0258] After the excess lithium powder had been separated off, thesolution of lithium trifluorotris(pentafluoroethyl)phosphate in dimethylcarbonate was analysed by ¹⁹F NMR and ¹H NMR spectroscopy. The spectrawere recorded using an FEP sample tube inside a 5 mm NMR tube with anacetone-D₆ film as external lock and CCl₃F in the film as reference. ¹⁹FNMR spectrum of the meridional form (≈85 mol %): −44.53 dm (PF); −79.90m (CF₃); −81.71 m (2CF₃); −87.77 dm (PF₂); −115.23 dm (3CF₂); J¹_(P,F)=888 Hz; J² _(P,F)=91 Hz.

[0259]¹⁹F NMR spectrum of the facial form (15 mol %): −67.98 dm; J¹_(P,F)=785 Hz (PF₃ group). Other signals of the facial form overlappedwith those of the meridional form.

[0260]¹H NMR spectrum (acetone-D₃ film, reference; TMS): 4.35 s (CH₃).

Example 33

[0261] 16.09 g of trifluorotris(pentafluoroethyl)phosphoric acid indimethyl carbonate, prepared as described in Example 20, were dilutedwith 6.78 g of dry dimethyl carbonate and reacted with 0.25 g of lithiumhydride, which was added to the reaction mixture in small portions withstirring using a magnetic stirrer and with cooling in an ice bath. Atthe beginning, this reaction mixture reacted vigorously with evolutionof hydrogen. When all the lithium hydride had been added, the mixturewas warmed to room temperature and stirred for a further hour.

[0262] After the excess lithium hydride had been separated off, thesolution of lithium trifluorotris(pentafluoroethyl)phosphate in dimethylcarbonate was analysed by ¹⁹F NMR and ¹H NMR spectroscopy. The spectrawere recorded using an FEP sample tube inside a 5 mm NMR tube with anacetone-D₆ film as external lock and CCl₃F as internal reference.

[0263]¹⁹F NMR spectrum of the meridional form (≈85 mol %): −44.07 dm(PF); −80.12 m (CF₃); −81.77 m (2CF₃), −87.52 dm (PF₂); −115.17 dm(3CF₂): J¹ _(P,F)=888 Hz; J² _(P,F)=87 Hz.

[0264]¹⁹F NMR spectrum of the facial form (≈15 mol %): −68.40 dm; J¹_(P,F)=795 Hz (PF₃ group). Other signals of the facial form overlappedwith those of the meridional form.

[0265]¹H NMR spectrum (acetone-D₃ film, standard: TMS): 4.21 s (CH₃).

[0266] This solution can be employed directly for the preparation ofelectrolytes for lithium batteries.

1. Acid of the general formula [I] [R_(y)PF_(6-y)]⁻H⁺  [I] where y=1, 2or 3, and in which the ligands R may be identical or different, and R isa perfluorinated C₁₋₈-alkyl or aryl group or R is a partiallyfluorinated C₁₋₈-alkyl or aryl group in which some of the F or H mayhave been substituted by chlorine.
 2. Acid according to claim 1,characterised in that at least one R is a nonafluorobutyl orpentafluorophenyl group, particularly preferably a pentafluoroethylgroup.
 3. Acid according to claim 1 or 2, characterised in that y=2 or3, preferably y=3.
 4. Acid according to one of claim 1 to 3:trifluorotris(pentafluoroethyl)phosphoric acid,trifluorotris(heptafluoro-n-propyl)phosphoric acid,trifluorotris(nonafluoro-n-butyl)phosphoric acid,tetrafluorobis(nonafluoro-n-butyl)phosphoric acid,pentafluoro(nonafluoro-n-butyl)phosphoric acid,tetrafluorobis(heptafluoro-i-propyl)phosphoric acid.
 5. Process for thepreparation of an acid according to one of claims 1 to 4, characterisedin that a perfluoroalkylphosphorane is reacted with hydrogen fluoride inthe presence of a suitable solvent and/or proton acceptor.
 6. Processaccording to claim 5, characterised in that the solvent and/or protonacceptor employed is water, alcohols, ethers, sulfides, amines,phosphines, carboxylic acids, esters, glycols, polyglycols, polyamines,polysulfides or mix- tures of at least two of these solvents and/orproton acceptors.
 7. Process according to claim 6, characterised in thatthe suitable solvent and/or proton acceptor is methanol, ethanol, aceticacid, dimethyl ether, diethyl ether, dimethyl carbonate, dimethylsulfide, dimethylformamide, triethylamine or triphenylphosphine, or amixture of at least two of these compounds.
 8. Process according to oneof claims 5 to 7, characterised in that the reaction of theperfluoroalkylphosphorane with a solution of hydrogen fluoride iscarried out in a solvent in a concentration of greater than 0.1% byweight of HF, preferably greater than 5% by weight of HF, particularlypreferably greater than 10% by weight and very particularly preferablygreater than 20% by weight, but less than 100% by weight, of HF. 9.Process according to one of claims 5 to 8, characterised in that thereaction of the perfluoroalkylphosphorane is carried out at atemperature of from −50 to +100° C., preferably at a temperature of from−35 to +50° C., particularly preferably at from 0 to 25° C.
 10. Solutionof an acid according to one of claims 1 to 4 and a solvent,characterised in that the acid is present in a concentration of greaterthan 2% by weight, preferably greater than 20% by weight, particularlypreferably greater than 70% by weight and very particularly preferablygreater than 80% by weight.
 11. Salt of the general formula [II][R_(y)PF_(6-y)]_(m) ⁻M^(m+)  [II] where M^(m+) is a monovalent, divalentor trivalent cation, m=1, 2 or 3 and y=1, 2 or 3, and in which theligands R may be identical or different, and R is a perfluorinatedC₁₋₈-alkyl or aryl group or R is a partially fluorinated C₁₋₈-alkyl oraryl group in which some of the F or H may have been substituted bychlorine.
 12. Salt of the general formula [II] according to claim 11,characterised in that it contains an Li, Zn, Mg, Cu, Ag, ammonium,phosphonium, oxonioum, sulfonium, arsonium, tropilium, a nitryl cation,a nitrosyl cation or a tris(dialkyl-ammino)carbonium cation.
 13. Processfor the preparation of a salt according to one of claims 11 and 12,characterised in that an acid according to one of claims 1 to 4 isreacted in a suitable solvent with a salt of the general formula [III]M^(m+)(A)^(m−)  [III] where M^(m+) is a monovalent, divalent ortrivalent cation, A is a basic or neutral anion or a mixture of basicanions or a mixture of at least one basic and at least one neutralanion, and m=1, 2 or 3, or with metals, metal hydrides, metal oxides ormetal hydroxides.
 14. Process according to claim 13, characterised inthat the salt of the general formula [III] contains at least one oxide,hydride, carbonate, hydroxide, chloride, fluoride, formate, acetateand/or trifluoroacetate anion.
 15. Process according to claim 13,characterised in that the metals employed for the neutralisation are Li,Na, K, Rb, Mg, Cs, Ca, Sr, Ba, Sc, Y, Yb, La, Al, In, Cd and/or Zn. 16.Process according to claim 13, characterised in that the oxides employedfor the neutralisation are Li₂O, Na₂O, K₂O, MgO, CaO, SrO, BaO, Sc₂O₃,Y₂O₃, Yb₂O₃, La₂O₃, Al₂O₃, CdO, ZnO, CuO, FeO and/or Fe₂O₃.
 17. Processaccording to claim 13, characterised in that the hydroxides employed forthe neutralisation are LiOH, NaOH, KOH, RbOH, CsOH, Mg(OH)₂, Ca(OH)₂,Sr(OH)₂, Ba(OH)₂, Cd(OH)₂, Zn(OH)₂, Sc(OH)₃, AI(OH)₃ and/or Cu(OH)₂. 18.Process according to claim 13, characterised in that the hydridesemployed for the neutralisation are LiH, NaH, CaH₂, YH₃ and/or AlH₃. 19.Use of a salt according to one of claims 11 and 12 as catalyst,phase-transfer catalyst, solvent, ionic liquid or conductive salt in theelectrolytes of electrochemical devices.
 20. Use of an acid according toone of claims 1 to 4 as catalyst in the preparation of organiccompounds.
 21. Use of an acid according to one of claims 1 to 4 asreplacement for the acids HPF₆ and/or HBF₄ in chemical reactions.